Currently, a wide range of materials are being used as barrier coatings for different applications. Among them, polymers and graphene have been the focus of many studies. Polymers are used in numerous industries due to their remarkable properties, including resistance to thermal degradation, resistance to chemical permeation, and good mechanical properties. On the other hand, graphene, a one-atom-thick and two-dimensional material, does not allow the permeation of gases or liquid molecules through its plane; thus, it has been considered one of the promising nanomaterials used in gas and liquid barrier applications and corrosion inhibition coatings.